JP2022137898A - container and preform - Google Patents

Abstract

To provide a container excellent in CO2 emission reduction, excellent in buckling strength and suppressed in yellowing, and a method for manufacturing the container.SOLUTION: The present invention provides a container containing polyester as a main component, in which the polyester contains recycled polyester and virgin polyester, and the virgin polyester is biomass polyester.SELECTED DRAWING: Figure 1

Description

The present invention relates to containers and preforms for the manufacture of such containers.

Conventionally, polyesters such as polyethylene terephthalate have been widely used in the manufacture of containers to be filled with beverages, etc., because they are excellent in mechanical properties, chemical stability, heat resistance, gas barrier properties, transparency, etc., and are inexpensive. ing.

Polyester is produced by using a diol compound and a dicarboxylic acid compound as raw materials and subjecting these raw materials to a polycondensation reaction. These raw materials are usually produced from petroleum, which is a fossil resource. For example, when the polyester is polyethylene terephthalate (PET), ethylene glycol is industrially produced from ethylene, and terephthalic acid is industrially produced from xylene.

Year by year, there is an increasing trend to substitute materials derived from fossil fuels for the purpose of considering the environment, especially for the purpose of reducing CO ₂ emissions. As an attempt to reduce the use of such fossil fuels, it has been proposed to use polyester obtained from biomass-derived raw materials. For example, Patent Document 1 proposes a method for manufacturing a bio-based PET container using a bio-based material.

Moreover, a method has been proposed in which polyester recovered from containers such as used PET bottles is made reusable and recycled into containers as recycled polyester. For example, in Patent Document 2, in order to reduce the amount of CO ₂ emissions, it is proposed to use polyester, which is made from polyester and which has been recovered and made reusable, for containers. .

Japanese translation of PCT publication No. 2012-519748 JP 2011-256328 A

As mentioned above, both biomass polyester and recycled polyester have _CO2 emission reduction properties. Among these, recycled polyester is superior to biomass polyester in reducing _CO2 emissions. Therefore, it is desirable to use only recycled polyester for containers.

This time, the present inventors have produced a container using only recycled polyester in consideration of CO ₂ emission reduction. However, the present inventors have noticed that the resulting container has a reduced buckling strength and the color of the container has turned yellow (yellowing).

The present invention has been made in view of the above findings, and its object is to provide a container that is excellent in reducing CO ₂ emissions and suppresses a decrease in buckling strength and yellowing, and a method for manufacturing the container. It is to be.
Another object of the present invention is to provide a preform for manufacturing this container and a method for manufacturing the preform.

The present invention is a container containing polyester as a main component,
The polyester includes recycled polyester and virgin polyester,
The container, wherein the virgin polyester is biomass polyester.

In the container according to the present invention, the mass ratio of the virgin polyester to the recycled polyester may be 0.11 or more and 2.33 or less.

In a container according to the invention, the volume to mass ratio may be greater than or equal to 5 mL/g and less than or equal to 50 mL/g.

A container according to the invention comprises a mouth, a neck, a shoulder, a body and a bottom,
A cross-sectional thickness of the trunk portion may be 0.05 mm or more and 0.54 mm or less.

The present invention is a preform for manufacturing the container.

The present invention provides a method for manufacturing the preform,
a step of dry blending the first pellets and the second pellets to obtain a mixture;
melting the mixture to obtain a melt;
injection molding the melt;
including
The first pellet is made of the recycled polyester,
Said 2nd pellet is a manufacturing method of a preform comprised from said virgin polyester.

The present invention provides a method for manufacturing the container,
A method for manufacturing a container, comprising blow-molding the preform obtained by the method for manufacturing a preform.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the container excellent in _CO2 emission reduction property, and the fall of buckling strength and yellowing being suppressed can be provided.
According to the present invention, a preform for manufacturing this container and a method for manufacturing the preform can be provided.

1 is a schematic half-sectional view of one embodiment of a container according to the invention; FIG. 1 is a schematic half-sectional view showing one embodiment of a preform according to the invention; FIG.

[container]
As used herein, the term "container" means a molded body that accommodates an article. Examples of the container include molded articles such as compression molded articles, injection molded articles, blow molded articles and thermoformed articles. Examples of specific containers include bottles, vials, cups, trays and packs.

The container according to the invention contains polyester as a main component. The polyester includes recycled polyester and virgin polyester, and the virgin polyester is biomass polyester. By configuring the container in this way, it is possible to obtain a container that is excellent in reducing CO ₂ emissions, and in which a decrease in buckling strength and yellowing are suppressed. The reason is considered as follows.
Recycled polyester is polyester that is recycled by collecting used containers and the like. The container before being recycled was also made from virgin polyester when it was first manufactured. When manufacturing a container from polyester, there is at least a step of melting the polyester. Therefore, when the recycled polyester is used to obtain a container, the recycled polyester has undergone at least two melting steps, the initial melting step and the melting step during recycling. Ester bonds present in polyesters are easily hydrolyzed, and hydrolysis is further accelerated under high temperature conditions. Every time the recycled polyester undergoes the melting process, the ester bond is hydrolyzed, resulting in the production of low-molecular-weight components such as monomers and oligomers. In general, recycled polyester undergoes solid phase polymerization to restore the reduced average molecular weight to its original state. Polyester contains more low molecular weight components than virgin polyester. As a result, it is considered that the buckling strength of the container is lowered.
In addition, the melting process is generally carried out in the atmosphere, and active gases such as oxygen in the atmosphere promote various decompositions or reactions other than the above hydrolysis, resulting in yellowing of the polyester. expected to occur.
The container according to the present invention combines virgin polyester, which has not been subjected to heat history, with recycled polyester, and uses biomass polyester as the virgin polyester, so that it has excellent CO ₂ emission reduction performance, and has reduced buckling strength and yellowing. change can be suppressed. A container having excellent buckling strength can be stacked in a larger number of cardboard boxes in which the container is packed, so that the storage efficiency in a warehouse is excellent.
In addition, the above-mentioned high-temperature conditions are temperature conditions at which the polyester is hydrolyzed in the atmosphere. Although not particularly limited, the high temperature condition is, for example, a temperature condition of 230° C. or higher.

The polyester, which is the main component of the container of the present invention, is polyester containing recycled polyester and virgin polyester made of biomass polyester. It can be identified by checking the distribution. For example, if the molecular weight distribution of recycled polyester and virgin polyester is unimodal, the molecular weight distribution of the polyester containing them will be bimodal. Thereby, the presence of two types of polyester can be confirmed. As described above, since the recycled polyester contains low-molecular-weight components, the confirmation of the molecular-weight distribution is performed in the molecular weight region of 10,000 or more.
As a GPC apparatus, "515 HPLC pump, 717 plus automatic injection device, 2487 ultraviolet-visible detector" manufactured by Nippon Waters Co., Ltd. can be used. As a column, "2x PLgel 5μ MIXED-D 7.5 x 300 mm" manufactured by Agilent Technologies, Inc. can be used.
In order to distinguish between the two peaks more clearly, the peaks may be waveform-separated. Waveform separation can be performed by fitting with Wesslau's lognormal distribution function. As waveform separation software, Igor (manufactured by WaveMetrics) can be used.

As used herein, "main component" means a component that accounts for more than 50% by mass of the total. The polyester content in the container is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more.

As used herein, "polyester" means a polymer polymerized by ester bonds. Such polyesters are usually obtained by polycondensation of a dicarboxylic acid compound and a diol compound.
Dicarboxylic acid compounds include, for example, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosandioic acid, pimelic acid, azelaic acid, methylmalonic acid and ethylmalonic acid, adamantane dicarboxylic acid, norbornene dicarboxylic acid, cyclohexanedicarboxylic acid, decalinedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1, 8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodiumsulfoisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenanthenedicarboxylic acid, 9,9'-bis (4-Carboxyphenyl)fluoric acid and their ester derivatives.
Examples of diol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, and cyclohexane. diethanol, decahydronaphthalenedimethanol, decahydronaphthalenediethanol, norbornanedimethanol, norbornanediethanol, tricyclodecanedimethanol, tricyclodecaneethanol, tetracyclododecanedimethanol, tetracyclododecanediethanol, decalindimethanol, decalindiethanol, 5 -methylol-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane, cyclohexanediol, bicyclohexyl-4,4'-diol, 2,2-bis(4-hydroxy cyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamandiol , paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane, pentaerythritol and bis-β-hydroxyethyl terephthalate (BHET).
The polyester is preferably polyethylene terephthalate or modified polyethylene terephthalate obtained by polymerizing a raw material monomer for polyethylene terephthalate and a copolymerization monomer.

The polyester may contain a monomer other than the dicarboxylic acid compound and the diol compound as long as the properties of the present invention are not impaired, but the content thereof is preferably 10 mol% or less with respect to all structural units. , is more preferably 5 mol % or less, and even more preferably 3 mol % or less.

The polyester may be polymerized using a polymerization catalyst. Polymerization catalysts include manganese catalysts, titanium catalysts, aluminum catalysts, lithium catalysts, germanium catalysts, antimony catalysts, and the like.

As used herein, "recycled polyester" refers to mechanically recycled polyester. Mechanically recycled polyester removes contaminants and foreign matter by sorting, pulverizing, and washing polyester containers to obtain flakes, which are further treated at high temperature and under reduced pressure for a certain period of time to remove contaminants inside the resin. It refers to the polyester obtained by The polyester constituting the polyester container may be polyester derived from fossil fuel or biomass polyester.
As used herein, "virgin polyester" refers to polyester that has not been recycled.

The virgin polyester contained in the polyester container according to the invention is biomass polyester. A biomass polyester is a polyester obtained from a raw material containing a biomass-derived monomer. Thus, biomass polyesters contain monomer units derived from biomass. Examples of biomass-derived monomers include biomass-derived diol compounds and dicarboxylic acid compounds. The diol compounds and dicarboxylic acid compounds include those listed above.
In the production of biomass-derived monomers, biomass such as sugar cane is used as a raw material, and processes such as fermentation, chemical reaction, and refining are performed. is used. Therefore, the biomass polyester contains at least a component derived from fossil fuel. Therefore, when comparing the CO ₂ emission reduction properties of recycled polyester and biomass polyester, recycled polyester is superior to biomass polyester in CO ₂ emission reduction properties.

In one embodiment, the biomass polyester is a polyester obtained from a raw material containing at least one compound selected from the group consisting of a biomass-derived diol compound and a biomass-derived dicarboxylic acid compound.
The biomass-derived diol compound and the biomass-derived dicarboxylic acid compound are described below.

A biomass-derived diol compound can be produced by a conventionally known method. Biomass-derived diol compounds, for example, can be produced directly from a carbon source such as glucose by fermentation, or can be produced by chemically converting dicarboxylic acids such as oxalic acid, dicarboxylic acid anhydrides, and cyclic ethers obtained by fermentation. may be manufactured by
When the diol compound is ethylene glycol, biomass-derived ethylene glycol is obtained, for example, by first producing ethanol (biomass ethanol) using biomass such as sugar cane as a raw material, and then ethanol is converted into ethylene or ethylene oxide by a conventionally known method. by making them and then converting them to ethylene glycol.

The biomass-derived dicarboxylic acid compound may be directly produced by the fermentation method described above, or may be produced by converting a product obtained by the fermentation method through a chemical reaction.
When the dicarboxylic acid compound is terephthalic acid, biomass-derived terephthalic acid is produced, for example, from corn, sugars, and wood to produce isobutanol, which is then converted to isobutylene, which is then dimerized to form isooctene. and then synthesized p-xylene via the method described in Chemische Technik, vol.38, No.3, p116-119; 1986, i.e., radical cleavage, recombination, cyclization, and then It can be produced by oxidation (International Publication No. 2009/079213).

Fossil fuel-derived monomers may be used along with biomass-derived monomers in the production of biomass polyesters. That is, the biomass polyester may contain monomer units derived from fossil fuels in addition to monomer units derived from biomass.

In the biomass polyester, the ratio of biomass-derived components can be confirmed by measuring the degree of biomass. As used herein, the term “biomass degree” is an index indicating the mass ratio of biomass-derived components. A method for calculating the degree of biomass will be described below.
Since carbon dioxide in the atmosphere contains a certain amount of C14 (105.5 pMC), plants that grow by taking in carbon dioxide in the atmosphere, such as corn, also contain about 105.5 pMC of C14. It is known that It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in all carbon atoms, the ratio of biomass-derived carbon can be calculated. Taking polyethylene terephthalate as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1. For example, when only biomass-derived ethylene glycol is used and only fossil fuel-derived terephthalic acid is used, the mass ratio of biomass-derived components in polyester is 31.25%, so the theory of biomass degree The value is 31.25%. This is because the mass of polyethylene terephthalate is 192, of which the mass derived from biomass-derived ethylene glycol is 60, so 60÷192×100=31.25.
In addition, when polyester is produced using raw materials of only fossil fuel-derived monomers, the mass ratio of biomass-derived components is 0%, so the biomass degree of polyester is 0%. A polyester having a biomass degree of 0% may be referred to as a fossil fuel polyester.

The biomass degree of virgin polyester made of biomass polyester is preferably 10% or more and 30% or less, more preferably 15% or more and 30% or less.
By setting the biomass degree to 10% or more, CO ₂ emission reduction can be further improved.
By setting the biomass degree to 30% or less, it is possible to use raw materials derived from fossil fuels that are cheaper than raw materials derived from biomass, and it is possible to obtain biomass polyesters that are less expensive.

In the container according to the present invention, the mass ratio of virgin polyester to recycled polyester is preferably 0.11 or more and 2.33 or less, more preferably 0.43 or more and 1.5 or less.
By setting the mass ratio to 0.11 or more, the decrease in the buckling strength and yellowing of the container can be further suppressed.
By setting the mass ratio to 2.33 or less, the CO ₂ emission reduction property of the container can be further improved.

In the container according to the present invention, the total content of recycled polyester and virgin polyester is preferably more than 50% by weight, more preferably 70% by weight or more, and even more preferably 90% by weight, relative to the total weight of the container. or more, and more preferably 99% by mass or more.

The container may contain additives as long as they do not impair the characteristics of the present invention, such as oxygen absorbers, gas barrier resins (nylon 6, nylon 6,6 and polymetaxylylene adipamide (MXD6)). polyamide), plasticizers, UV stabilizers, antioxidants, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, release agents, Antioxidants, ion exchange agents, acetaldehyde absorbents (eg, AA Scavengers from Color Matrix) and coloring agents are included.

An embodiment of the container structure according to the present invention will now be described with reference to FIG.

FIG. 1 is a schematic half-sectional view showing one embodiment of a container 10 according to the present invention. The container 10 includes a mouth portion 11, a neck portion 12, a shoulder portion 13, a body portion 14, and a bottom portion 15, as shown in FIG.

In one embodiment, the spout 11 comprises a threaded portion 16 to which the cap is screwed, a turnip 17 below the threaded portion 16, and a support ring 18 below the turnip 17, as shown in FIG.

In one embodiment, neck 12 is located between support ring 18 and shoulder 13 and has a generally cylindrical shape with a generally uniform diameter, as shown in FIG. Moreover, in one embodiment, the shoulder portion 13 has a cylindrical shape whose diameter gradually increases from the neck portion 12 side toward the body portion 14 side.

In one embodiment, body 14 is located between shoulder 13 and bottom 15, as shown in FIG. In one embodiment, the body 14 also includes a panel portion 21 into which the body 14 is recessed, as shown in FIG. With such a configuration, deformation of the container due to increase/decrease in internal pressure can be prevented when the container is filled with heated contents or when the container is heated after being filled with the contents.
In addition, since the container according to the present invention suppresses a decrease in buckling strength, the shape of the body can be appropriately selected. That is, it is no longer necessary to form the body of the container into a shape suitable for buckling strength, and various shapes can be selected.

In one embodiment, as shown in FIG. 1, the bottom portion 15 includes a centrally-located recessed portion 19 and a ground portion 20 provided around the recessed portion 19. At this ground portion 20, the trunk portion 14 are connected. With such a configuration, deformation of the container due to an increase or decrease in internal pressure can be prevented when the container is filled with heated contents or polyester is heated after being filled with the contents.
In one embodiment, the "bottom part" means the inner part from the ground part when the container is made to stand on its own.

Since the container according to the present invention has a suppressed reduction in buckling strength, it is possible to maintain a high volume-to-mass ratio (volume/mass). As a result, it is possible to prevent the excessive use of polyester, reduce the amount of polyester that is disposed of, and improve the reduction of the environmental load, as well as improve the blow moldability of the container. It is preferably 5 mL/g or more and 50 mL/g or less, more preferably 8 mL/g or more and 50 mL/g or less.

In the container according to the present invention, the reduction in buckling strength is suppressed, so the thickness of the container can be reduced. As a result, it is possible to prevent the excessive use of polyester, reduce the amount of polyester that is disposed of, and thereby improve the reduction of the environmental load and improve the blow moldability of the container. The thickness of the cross section is preferably 0.05 mm or more and 0.54 mm or less, more preferably 0.05 mm or more and 0.5 mm or less.
The thickness means the thinnest portion of the cross section.

A container according to the present invention may have a single-layer structure or a multilayer structure of two or more layers. Moreover, when the container has a multilayer structure, each layer may have the same composition or different compositions.

In one embodiment, the container may have a deposited film on its surface. Thereby, the gas barrier properties of the container can be improved.

Examples of deposited films include metals such as aluminum, inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide, hexamethyldisiloxane, and the like. organic silicon compounds, and a hard carbon film such as a DLC (Diamond Like Carbon) film.
A hard carbon film made of a DLC film is a hard carbon film also called an i-carbon film or a hydrogenated amorphous carbon film (aC:H) ^, and is an amorphous carbon film mainly composed of SP3 bonds. is.

Also, the thickness of the deposited film is not particularly limited, and can be, for example, 1 nm or more and 150 nm or less.

Formation of the deposited film can be performed using a conventionally known method, for example, a physical vapor deposition method (physical vapor deposition method, PVD method) such as a vacuum deposition method, a sputtering method and an ion plating method, and a plasma A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a chemical vapor deposition method, a thermal chemical vapor deposition method, and a photochemical vapor deposition method can be used.
In addition, the thickness of the deposited layer can be measured, for example, at the body of the container, and means the point where the thickness is the thinnest.

[Container manufacturing method]
A container according to the present invention can be manufactured by blow molding a preform described later. Blow molding can be performed by a conventionally known method.

[preform]
As used herein, a preform is a preform prior to blow molding of a container. The preform according to the invention is used for manufacturing the container according to the invention. Therefore, the preform according to the present invention contains polyester as a main component, and the polyester includes recycled polyester and virgin polyester, and the virgin polyester is biomass polyester. The container according to the present invention can be manufactured by configuring the preform in this manner.
Incidentally, the polyester contained in the preform according to the present invention can be the same as that used for the container according to the present invention.

An embodiment of the structure of the preform according to the invention will now be described with reference to FIG.

FIG. 2 is a schematic half-sectional view showing one embodiment of the preform according to the present invention. The preform 30 includes a mouth portion 31 , a body portion 32 connected to the mouth portion 31 , and a bottom portion 33 connected to the body portion 32 as shown in FIG. Of these, the mouth portion 31 corresponds to the mouth portion 11 of the container 10 and has substantially the same shape as the mouth portion 11 . The body portion 32 corresponds to the neck portion 12, the shoulder portion 13 and the body portion 14 of the container 10, and has a substantially cylindrical shape. The bottom portion 33 corresponds to the bottom portion 15 of the container 10 and has a substantially hemispherical shape.

The mouth portion 31 includes a screw portion 34 corresponding to the screw portion 16 of the container 10 to which a cap (not shown) is screwed, a cover 35 provided below the screw portion 34 and corresponding to the cover 17 of the container 10 , and a cover 35 . , and has a support ring 36 corresponding to the support ring 18 of the container 10 . The shape of the mouth portion 31 may be a conventionally known shape.

The cross-sectional thickness of the preform according to the present invention is preferably 1.3 mm or more and 4.7 mm or less, more preferably 2.1 mm or more and 4.0 mm or less. By setting the thickness of the cross section within the above range, the container according to the present invention can be manufactured.
The thickness of the cross section of the preform can be measured, for example, at the body portion of the preform, and means the point where the thickness of the cross section is the thinnest.

[Preform manufacturing method]
A method for producing a preform comprises the steps of: dry-blending first pellets and second pellets to obtain a mixture; melting the mixture to obtain a melt; injection molding the melt; including. The first pellets are composed of recycled polyester and the second pellets are composed of virgin polyester.
In addition, in the preform manufacturing method according to the present invention, the same recycled polyester and virgin polyester as used in the container according to the present invention can be used. That is, the virgin polyester used in the preform manufacturing method according to the present invention is biomass polyester.

The method for producing the preform preliminarily dry blends the first pellets made of recycled polyester and the second pellets made of virgin polyester before melting them. By adopting such a process, a container in which the recycled polyester and the virgin polyester are uniformly dispersed can be produced.

In the preform manufacturing method, the mixing ratio of the second pellets to the first pellets is preferably 0.11 or more and 2.33 or less, more preferably 0.43 or more and 1.5 or less, on a mass basis.

In the preform manufacturing method, the melting of the first pellets and the second pellets can be carried out by a conventionally known method. The melting temperature is not particularly limited as long as it is a temperature at which the first pellet and the second pellet are melted.
In addition, in this specification, "melting temperature" refers to the temperature of melted polyester.

In the preform manufacturing method, the step of injection molding the melt can be performed by a conventionally known method.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Example 1]
Pellets of mechanically recycled polyester (manufactured by Kyoei Sangyo Co., Ltd., NA-BT7906) and virgin polyester made of pellets of biomass polyester (manufactured by Mitsui Chemicals, Inc., SA135T (B), biomass content of 30%) were prepared. .
First, 70 parts by mass of mechanically recycled polyester pellets and 30 parts by mass of virgin polyester pellets were dry-blended. Next, the resulting mixture was melted and the melt was injected using an injection molding machine to produce a preform shown in FIG.
The thickness of the body of the preform was 3.5 mm, and the basis weight was 21 g.

Next, the preform was heated to 110° C. and biaxially stretched blow-molded in a blow-molding mold to produce a container with an internal capacity of 500 mL as shown in FIG. The cross-sectional thickness at the body of the container was 0.32 mm. The volume/mass ratio of the polyester composing the container was 23.8.

[Example 2]
A preform was produced in the same manner as in Example 1, except that 50 parts by mass of the mechanically recycled polyester pellets and 50 parts by mass of the virgin polyester pellets were dry-blended to obtain a mixture.

Then, in the same manner as in Example 1, a container was produced from the above preform. The polyester composing the container had a volume/mass ratio of 23.8.

[Comparative Example 1]
A preform was produced in the same manner as in Example 1, except that only pellets of the mechanically recycled polyester were used.

Then, in the same manner as in Example 1, a container was produced from the above preform. The polyester composing the container had a volume/mass ratio of 23.8.

[Comparative Example 2]
A preform was produced in the same manner as in Example 1, except that only virgin polyester pellets made of biomass polyester (SA135T (B), manufactured by Mitsui Chemicals, Inc., biomass content 30%) were used.

Then, in the same manner as in Example 1, a container was produced from the above preform. The polyester composing the container had a volume/mass ratio of 23.8.

<<Evaluation of _CO2 emission reduction>>
The ratio X of the fossil fuel-derived raw material contained in the virgin polyester made of biomass polyester with respect to the total mass of the polyester contained in the container was calculated based on the following formula (1). Table 1 shows the calculation results.
X=α×(1-(biomass degree/100))/(α+β) (1)
α: Mass of virgin polyester from biomass polyester contained in the container β: Mass of mechanically recycled polyester contained in the container

<<Measurement of buckling strength>>
After filling 500 ml of the content liquid (water) into each of the containers produced in the above examples and comparative examples, the containers were sealed with caps. A buckling strength test was performed on each container in an upright state. A top load tester (buckling tester) EH-1000 manufactured by Evic Co., Ltd. was used to measure the buckling strength. A load was applied from the top of the mouth at a constant rate, and the maximum load at which a so-called yield state occurred was taken as the buckling strength. Table 1 shows the measurement results.

<<Measurement of color>>
A sample obtained by finely cutting only the mouth portion of the polyester container produced in the above Examples and Comparative Examples was precooled under liquid nitrogen for 10 minutes using a freeze crusher (manufactured by SPEX, Model 6870 Freezer/Mill). A powder was obtained by freeze-milling for 10 minutes under nitrogen. Then, this powder is measured with reflected light using a spectral colorimeter (CMS-35SP, manufactured by Murakami Color Research Laboratory Co., Ltd.) to determine the L ^* value and a ^* value in the L ^* a ^* b ^* color system. and b ^* values were measured. The measurement conditions were SCE (exclude specular reflection), 10° field of view, and D65 light source. In addition, the measurement was performed based on JISZ8722:2009. Table 1 shows the measurement results.

Compared to the container of Comparative Example 2, which uses only virgin polyester made of biomass polyester, the containers of Examples 1 and 2 have a smaller ratio X of the fossil fuel-derived raw material contained in the virgin polyester made of biomass polyester. Excellent in reducing _CO2 emissions.
The containers of Examples 1 and 2 exhibit less reduction in buckling strength than the container of Comparative Example 1, which uses only mechanically recycled polyester.
Compared with the container of Comparative Example 1, the containers of Examples 1 and 2 have a smaller b ^* value representing yellowness, and thus yellowing is suppressed.

10: Container 11: Mouth 12: Neck 13: Shoulder 14: Body 15: Bottom 16: Screw 17: Turnip 18: Support ring 19: Depression 20: Ground 21: Panel 30: Preform 31: Mouth 32: Body 33: Bottom 34: Screw 35: Turnip 36: Support ring

Claims (7)

A container containing polyester as a main component,
The polyester includes recycled polyester and virgin polyester,
A container, wherein the virgin polyester is biomass polyester. 2. The container according to claim 1, wherein the mass ratio of said virgin polyester to said recycled polyester is 0.11 or more and 2.33 or less. 3. The container according to claim 1 or 2, wherein the volume to mass ratio is 5 mL/g or more and 50 mL/g or less. comprising a mouth, a neck, a shoulder, a body and a bottom,
The container according to any one of claims 1 to 3, wherein the cross-sectional thickness of the body is 0.05 mm or more and 0.54 mm or less. A preform for manufacturing a container according to any one of claims 1 to 4. A method for manufacturing a preform according to claim 5,
a step of dry blending the first pellets and the second pellets to obtain a mixture;
melting the mixture to obtain a melt;
injection molding the melt;
including
The first pellet is made of the recycled polyester,
The method for producing a preform, wherein the second pellets are made of the virgin polyester. A method for manufacturing a container according to any one of claims 1 to 4,
A method for manufacturing a container, comprising a step of blow molding a preform obtained by the method for manufacturing a preform according to claim 6.

Images